Under water venting system for marine fuel tanks



March 19, 1963 5, vo cH 3,081,730

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STANLEY l. DVORAOHEK United States Patent 3,081,730 UNDER WATER VENTING SYSTEM FOR MARINE FUEL TANKS Stanley J. Dvorachek, 54 Benedict fit, Norwalk, Conn. Filed Sept. 4, 1958, Ser. No. 758,992 2 Claims. (Cl. 114-211) This invention relates to boats and more particularly to motor boats.

It is an object of the present invention to provide a venting system for fuel tanks of motor boats that will effectively prevent fire and explosions that might otherwise result from improper disposal of highly volatile gases in the vicinity of the boat during the filling of the fuel tank.

Another object of the present invention is to provide a venting system of the above type for marine fuel tanks that will efiectively discharge all volatile vapors beneath the surface of the water as the fuel tank is being filled, and will further allow fresh air to be drawn into the tank to replace the fuel as it is consumed, while preventing water from being drawn into the tank.

Other objects of the invention are to provide a venting system for marine fuel tanks bearing the above objects in mind which is of simple construction, has a minirnum number of parts, is inexpensive to manufacture, and is efficient in operation.

For other objects and for a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a fragmentary longitudinal cross-sectional View of a boat provided with a venting system made in accordance with the present invention;

'FIGURE 2 is an enlarged longitudinal cross-sectional view of a control valve forming a part of the present invention;

FIGURE 3 is an enlarged fragmentary longitudinal cross-sectional view of a filler pipe assembly forming another part of the present invention; and

FIGURE 4 is a fragmentary side elevational view, partly in section, of a slightly modified form of the filler pipe assembly.

Referring now more in detail to the drawing, and more particularly to 'FIGURE 1 thereof, a fuel system made in accordance with the present invention is shown to include a fuel tank that has a fuel supply line 12 communicating with the power plant of the vessel 13. The fuel tank 10 also is provided with a filler pipe 14 through which fuel may be supplied from a nozzle 15 during the fueling of the vessel. A fiat metallic ring 18, a flat resilient seal ring 20, and a flat ring 22 are supported in stacked relationship upon the upper end of the filler pipe 14, by being threaded into a fitting which is threaded externally on the filler pipe 14. The upper ring 22 has a central opening of only slightly larger diameter than the nozzle 15, the resilient seal ring has a central opening of slightly smaller diameter than the nozzle 15, and the lowermost ring 18 has a central opening of slightly larger diameter than the central opening of the upper ring 22. The fitting 24 has a mounting flange 26 by which it is secured to the deck of the boat by means of screws passing through openings 28 in the flange and, when the nozzle 15 is inserted through the openings in the rings, the inner edge of the seal ring engages the outer surface of the nozzle and seals the space between the nozzle and the inside of a fuel pipe 14. This effectively prevents the escape of vapors outwardly through the filler pipe 14 during the fueling of the vessel, while the metallic rings further prevent formation and discharge of static charges that might cause explosion or fire.

Patented Mar. 19, 1963 As is well known to those skilled in the art, it is neces sary to provide a vent for allowing vapors contained within the tank 10 to pass outwardly during the filling of the tank with fuel, since the vapors would otherwise be compressed and present a constant hazard. In accordance with the present invention, such venting is provided for by means of a vent duct 29 connected to the top of the tank 10 communicating at one end with the interior thereof, and with its opposite end communicating with the inlet 30 and central passageway 31 of a control valve unit 32. A normally closed check valve member 34 allows the outward flow of displaced vapor from the common passageway 31 into the outlet 36 that is connected to a vent pipe 38 passing through the hull 39 of the vessel below the water line thereof so as to discharge into the water. The opposite end of the common passageway 31 within the control member 32 is provided with a normally closed check valve member 40 that allows fresh air to flow into the common passageway 31 and int-o the interior of the tank 10 in response to negative pressure therewithin created by the drawing of fuel outwardly through the fuel supply line 12 during the operation of the power plant.

The operation of this system will now be readily understood. As a nozzle 15 is inserted into the filler pipe 14 during the fueling of the tank 10, the space: between the nozzle and the filler pipe is sealed so that any vapors that are forced outwardly through the vent 29, by the newly received fuel are automatically vented into the water through the vent pipe 38, by means of the opening of the check valve 34, while the other check valve 40 remains closed. After the filter pipe is closed, the fuel leaving the tank 10 creates a negative pressure therewithin which is relieved by fresh air passing into the common passageway 31 and vent duct 29 by the opening of the check valve 40, while the check valve 34 remains closed.

In FIGURE 4 of the drawing, a slightly modified form of filler pipe construction is shown to include a different type of fitting 24a that is threadedly secured to the upper end of the filler pipe 14 and provided with a threaded neck 25 to which the filler pipe 15 may be threadedly connected, if so desired. This fitting may also be provided with a mounting flange 25a to secure it to the deck of the vessel and to prevent movement or displacement thereof during use.

While various changes may be made in the detail construction, it shall be understood that such changes shall be within the spirit and scope of the present invention as defined by the appended claims.

What I claim as new and desire to protect by Letters Patent of the United States is:

1. A marine fuel system comprising in combination, a fuel tank, a filler pipe leading into the tank for admission of fuel, a resilient seal ring mounted on said filler pipe, said seal ring projecting inwardly and having means forming an opening for sealing the space between the filler nozzle and the filler pipe against the escape of fuel and vapors during the admission of fuel into the tank, seal ring retaining means engaging both sides of said seal ring and engaging said filler pipe, a fuel discharge line leading from said tank, a control valve having a vapor outlet port for discharging vapors and an air inlet port for admitting air, a vent pipe connecting said control valve to the upper part of said tank, a vapor discharge pipe connected to said vapor outlet port and terminating remotely from the fuel system, and check valve means in said control valve pre venting outward fiow through said air inlet port and inward flow through said vapor outlet port.

2. The fuel system as defined in claim 1, wherein said seal ring retaining means comprises a pair of threaded metal rings sandwiching said seal ring at the seal ring periphery and said filler pipe is provided with internal threads engaged by said metal rings.

References Cited in the file of this patent UNITED STATES PATENTS Whiting Feb. 2, 1943 10 Parker Oct. 19, 1943 Garretson Aug. 23, 1949 Anderson Dec. 19, 1950 Peff Apr. 22, 1952 Kiehaefer Feb. 3, 1953 Rieke Dec. 18, 1956 Smith May 12, 1959 Basore July 12, 1960 

1. A MARINE FUEL SYSTEM COMPRISING IN COMBINATION, A FUEL TANK, A FILLER PIPE LEADING INTO THE TANK FOR ADMISSION OF FUEL, A RESILIENT SEAL RING MOUNTED ON SAID FILLER PIPE, SAID SEAL RING PROJECTING INWARDLY AND HAVING MEANS FORMING AN OPENING FOR SEALING THE SPACE BETWEEN THE FILLER NOZZLE AND THE FILLER PIPE AGAINST THE ESCAPE OF FUEL AND VAPORS DURING THE ADMISSION OF FUEL INTO THE TANK, SEAL RING RETAINING MEANS ENGAGING BOTH SIDES OF SAID SEAL RING AND ENGAGING SAID FILLER PIPE, A FUEL DISCHARGE LINE LEADING FROM SAID TANK, A CONTROL VALVE HAVING A VAPOR OUTLET PORT FOR DISCHARGING VAPORS AND AN AIR INLET PORT FOR ADMITTING AIR, A VENT PIPE CONNECTING SAID CONTROL VALVE TO THE UPPER PART OF SAID TANK, A VAPOR DISCHARGE PIPE CONNECTED TO SAID VAPOR OUTLET PORT AND TERMINATING REMOTELY FROM THE FUEL SYSTEM, AND CHECK VALVE MEANS IN SAID CONTROL VALVE PREVENTING OUTWARD FLOW THROUGH SAID AIR INLET PORT AND INWARD FLOW THROUGH SAID VAPOR OUTLET PORT. 